strut replacement documentation

[hangarb7]

Greetings,

So new struts are on airplane and getting ready for an annual. What documentation is required for the strut replacement? Just a logbook entry?

Does an IA have to sign off the replacement as an airframe mod/change or can an A&P just verify everything?

Thanks,

JackD
'46 BC12D

[Guest]

Re: strut replacement documentation

Hi Jack,

Did your A&P install the struts?

He should know the answer to the question you are asking.

Have you asked him yet?

Dave R

[hangarb7]

Re: strut replacement documentation

I installed the struts under the supervision of another A&P but he bailed on me (works another job and has moved)

Since the new struts from Wag Aero look so different in shape, this A&P asked the question of me. Just wanted to see what the forum suggested.

Thanks,

JackD

[Guest]

Re: strut replacement documentation

I installed the struts under the supervision of another A&P but he bailed on me (works another job and has moved)

Since the new struts from Wag Aero look so different in shape, this A&P asked the question of me. Just wanted to see what the forum suggested.

Thanks,

JackD

Hi Jack,

Golly, he should know the answer all by himself.

Internet gab spots is no place for an A&P to be looking for that info.

Ask him to read the AD, part 43 and part 43 appendix A.

Dave R.

[Guest]

Re: strut replacement documentation

Maybe he is he a new A&P?

[hangarb7]

Re: strut replacement documentation

Sorry Dave, I guess I wasn't clear.

I just contacted him yesterday and he hasn't even met me or seen the airplane. He just asked that on the telephone call.

Jack

[Guest]

Re: strut replacement documentation

Hi,

I see.

From part 43 appendix A there is this summary heading defining major repairs;

(b) Major repairs—(1) Airframe major repairs. Repairs to the following parts of an airframe and repairs of the following types, involving the strengthening, reinforcing, splicing, and manufacturing of primary structural members or their replacement, when replacement is by fabrication such as riveting or welding, are airframe major repairs.

Replacing struts with PMA struts does not qualify as a major so it is merely a logbook entry.

The AD has re inspection requirements for the fitting but that may actually be a separate AD I don't recall but he should read that and comply when he does the strut installation.

As the owner you are required to keep the AD status not the A&P (see part 91) so make sure you keep a nice set of records.

Dave R

[astjp2]

Re: strut replacement documentation

It all depends on if the WAG strut was built under an STC, if so, just do a 337 for installation compliance.."installed wag aero strust part #---- IAS stc ---, this is terminates repetitive inspection IAW AD---Para.--- section---. Weight and balance updated as required. END" and then just mail to OK city. Then a corresponding log book entry, "installed wag aero struts per stc---and AD--- see faa form 337 dated ---. signature, date cert. number. no fsdo involvement because the data is already approved by the STC and AD, the installation is approved by the IA's signature for return to service.

[Guest]

Re: strut replacement documentation

It all depends on if the WAG strut was built under an STC, if so, just do a 337 for installation compliance.."installed wag aero strust part #---- IAS stc ---, this is terminates repetitive inspection IAW AD---Para.--- section---. Weight and balance updated as required. END" and then just mail to OK city. Then a corresponding log book entry, "installed wag aero struts per stc---and AD--- see faa form 337 dated ---. signature, date cert. number. no fsdo involvement because the data is already approved by the STC and AD, the installation is approved by the IA's signature for return to service.

Good point about if they are STC'ed maybe some are but WagAero's and Univair's are PMA parts.

[Garry Crookham]

Re: strut replacement documentation

This discussion is probably a bit confusing to most aircraft owners without a maintenance background. PMA stands for Parts manufacturing Approval. A company that wants to produce parts to be installed on a type certificated aircraft is required to get a PMA on the parts to be produced and cannot legally produce the parts for sale without a PMA. The PMA part is usually an identical replacement for the subject part, or could have minor modifications that the PMA holder has cleared with the FAA. If a major change has been made to the part then an STC is usually required for installation. A part with a PMA is considered an approved replacement part if it is listed on the PMA holders eligibility list ( a list detailing what aircraft the part can be installed on). Parts produced by the aircraft manufacturer don’t need a PMA since they hold the type certificate for the airplane.

Per the strut discussion: If you purchase PMA struts (make sure your aircraft type is on the eligibility list) a logbook entry is all that is required. If the struts are an STC item then a Form 337 is required since it is considered a major alteration. And if you purchase the struts from the aircraft manufacturer a logbook entry is all that is required.

[astjp2]

Re: strut replacement documentation

All parts are required to be PMA'd or other spec like a TSO, etc. unless there is a drawing to build an owner produced part. It still may require an STC...its like saying that your airplane has a Lycoming O-320 and you replace it with an O-360, both are PMA, but there still needs to be approval to install it. The PMA alone is not enough. The airframes struts have a PMA, that is the approval to build them, they also have an STC because they are not the OEM.

[Guest]

Re: strut replacement documentation

All parts are required to be PMA'd or other spec like a TSO, etc. unless there is a drawing to build an owner produced part. It still may require an STC...its like saying that your airplane has a Lycoming O-320 and you replace it with an O-360, both are PMA, but there still needs to be approval to install it. The PMA alone is not enough. The airframes struts have a PMA, that is the approval to build them, they also have an STC because they are not the OEM.

Yes STC's require PMA for their parts too.

There really is no end to the ambiguity and recursion is there?

I suspect that when many of us say "PMA parts" that we also mean "no STC" even though it is unspoken.

Dave R

[PA1195]

Re: strut replacement documentation

My take on Airframe's struts is that they're FAA/PMA and STC'd because they may be made from strut material used for other aircraft like Pipers...wider chord or some other spec like material. They resemble Piper Cub struts. I was told they were 2# lighter the set than the OEM struts. Didn't confirm that however.

Gary

[Guest]

Re: strut replacement documentation

My take on Airframe's struts is that they're FAA/PMA and STC'd because they may be made from strut material used for other aircraft like Pipers...wider chord or some other spec like material. They resemble Piper Cub struts. I was told they were 2# lighter the set than the OEM struts. Didn't confirm that however.

Gary

Hi Gary,

There were Taylorcrafts made with the wide cord material like the Pipers.

Not a lot but there were some.

I am working on a PMA for the taper axle and the ACO seems willing to do it by STC (and associated PMA for STC parts) or by PMA only for a direct replacement part (no STC).

The difference in the two from the perspective of the applicant is ease of processing the paperwork.

Dave R

[PA1195]

Re: strut replacement documentation

The other possible anomaly with Airframes' struts is their chord is slightly offset relative to the aircraft's fuselage level or thrust line. Their chord visibly follows/is parallel to the lower fitting and adjacent longeron to which they're attached. Maybe they all do that regardless of manufacture?

Picture: http://www.airframesalaska.com/Taylo...-tcraftset.htm

Gary